The present invention refers to a construction system for buildings in general and housing in particular.
For some years now, buildings have been constructed with walls of different thicknesses for support and enclosing, of 30 cm and 15 cm, respectively, with solid bricks of about 14 cm.times.28 cm.times.5 cm, as an average measurement, after making the foundations with the same bricks or piles, pilettes and foundation plates according to the type of soil and load magnitudes, etc..
Once the soil level is reached, a waterproof layer is layed and levelled, vertical rules or strings to define the vertical plane of a wall to be built are placed as well as strings to define the horizontal rows of bricks.
In this way, one can at least get the wall to be straight and uniform, since brick sizes since they lack standardization and generally vary. The walls are then coated, thereby levelling the uneven thickness thereof, after placing a vertical waterproof coating or else the bricks are left visible.
In order to carry out this job, the bricklayers wet the bricks to enhance adhesiveness of the cement or mixture used to join them. The bricks are therefore aligned and levelled by knocking them gently, removing the excess cement and continuing with the next row, offsetting the bricks so that they interlock or else placing some crosswise according to the desired width and aspect of the wall.
This conventional process is slow and work needs to be stopped for the day once a certain height is reached to allow the cement to set partially and convey minimmum strength to the wall to avoid it being flipped over by the wind and other factors.
The same bricks may be used for the enclosure or inside walls although hollow or machine ceramic bricks of different thicknesses are preferred when there is a concrete structure. These bricks have uniform measures, since they are manufactured with extruder machines. They therefore use up less cement and are also lighter.
In general, these walls are coated with sand-based mixtures, lime, etc. or plaster. The process is also slow, requiring the use of vertical guides and strings.
To build supporting and non-supporting walls, hollow concrete blocks are built, of e.g. 20 cm.times.20 cm.times.40 cm, for the outer or supporting walls and 10 cm.times.20 cm.times.40 cm for the inner walls and special pieces are made for corners, door and window frames, lintels, etc.. The blocks are heavy and, preferebly, grey coloured. The wall should be of a certain length, have expansion control joints to avoid cracking and a proper foundation to avoid settling and consequent fissures, since they resist compression well but not traction. They are placed with cement.
It is also necessary in this case to use strings or vertical guides when placing the blocks for the wall to rise in a vertical plane and strings for the blocks to be at the same level. They are generally left uncoated.
This process is also slow.
Other techniques exist for building walls, bound within the so-called heavy prefabrication, based on large-sized, heavy panels or plates of prestressed or reinforced concrete, which require the use of cranes for transfering and placing. These elements are generally built off-site in plants using machines for filling, vibrating, moving moulds and curing, etc., requiring considerable investments.
Other systems exist based on the use of the so-called plaster table, which comprises a plaster panel coated on the outside with 7- or 9-mm thick paper. Since the plaster is a hygroscopic material, they may not be used for outside walls on the side exposed to rain.